James maodonald



(No ModeL) vJQm01)ONALD.

v HYDROSTATIC LEVELING IISTRUIMENT.A No. 327,564. C'

Patented Oct. 6*, 1885.

l a I F armlrlgly/V//M/ @Imm T.4 Ill.. lili i .Tovall it con/centri" i*Y the following attached to the standards respectively.

air to said tubes respectively may be automatically closed, so as toprevent a loss of I 4 tubes.

" s* 'UNiTEnfSTATES A the purpose of ascertaining the levels of dif-`aviones-imite.; ve

C p .1. ,i v wmf.. ig v t SPECIFICATION forming partoiLettersPatent No.327,S.6 4..dated Ocizo `vApplioatioxilil,ed une 1.11, 1885iV Beitiknown` thatI, JAMnsMnonoNALn, of".`

ytheicity, county,- and StateofNewgYork, have,v y l inventedcertain newand useful Improvements in Hydrostatio Levelingflnstrumentsmf-whieh isa. description, referencebeing had tothe accompanying drawings, inwhich-` Figure 1 is a view of said instrument, one ofthe stauidard'sbeing shown in section and, the other in elevation, the connecting-tubeof s which is broken. Fig. 2 is an enlarged'vertical sectional viewindetail of a portion of the top of one of the tubes, showing theconstruction of the valve therein. Fig. 3 is a bottom view of the screwcap and valve, taken on the line a: ai, Fig. 2, viewed in the directionof the arrow there shown. Fig. 4 is a plan view of the ring-nut by whichthe inner tube is fastened within the'case, and Fig. 5 is a plan view indetail of one of the ring clasps or indicators Like letters of referenceindicate like parts in the diiierent figures.

My invention relates to certain improvements in hydrostaticleveling-instruments for ferent planes of varying altitude, where it isimpracticable, by reason of intervening obstructions or otherwise, toutilize the ordinary level; and my object is, rst, to provide a simpleand effective means to ascertain and gage the height of the liquid inthe respective tubes with the utmost accuracy, in connection with asuitable scale; second, to provide a simple and effective means whereby,when said level has once been attained, the liquid in said tubes may betemporarilypieserved in a iixed position while theinstrument is removedfor examination; and, third, to provide a'valve mechanism whereby thevent which supplies liquid upon an accidental overturning of the In thedrawings, A A represent two standards, which consist of hollow shells orcylinders, preferably ofbrass', eaohof which is provided vvith asuitable base, A', into which the same is inserted and attached by meansof cement, a serewthread, or otherwise.

Within the shells Aareinsertcd glass tubes harmless. l

.a BT; aus at rserves ,h

placed rubber fringe .on,Washerslala-,FigsJP 1 and 2," whenV the. 1wholeis. secured,y .irmly; in placeby, means of a screw-ring, vk1;providedwith. slots 112,11?,

of the top of the shell A, s'uicient space being ...left above thesamelfor thereceptionofa screwthreaded. cap, `G. Said -capisprovidedwith the usual milledfangteaeenbral .Groninger plate, p2,-,better n preferably a perforation,`.c, and` a rbottom.

swaged into position, as shown, .leavingl space or chamber, c, betweensaid plate and the top, into which is loosely inserted an invertedconoidal-shaped cup or valve, D, the lower end of which is caused toprotrude Fig. 4,. wherebyth same muy..L besorewedwithin.thescrew:threaded interior through the plate c2 in order toretain the same in an upright position, while said protruding portionis-made smaller than that above, leaving a shoulder, d, thereon toretain said cup within the cavity c3. The perforation in the plate o2through which said cup protrudes is made preferably of a triangular orother irregular shape, as shown in Fig. 3, so that, while the cup D isprevented from moving laterally, one or more air-passages is provided atthe side thereof, so that` when the cup is in its normal position, asshown in Fig. 3, the air is free to pass downwardly through the vent c',around the cup and intoy the tube B.

The interior of the base A is bored downwardly, as at a, Fig. 1, so asto communicate with a lateral opening or passage, a.

Tubes or'neeks A2 A2 are screwed into the base A' to communicate withsaid tubes being provided with the usual con rugations or enlargementsfor the reception and retention of a exible rubber tube, E, stretchedthereover, by which. said standards arev connected. Each of said necks Ais provided with a stopcock or cut-oil', it, for the purposeshereinafter named.

Upon opposite sides of each of the shells A, I place slots a3 a?, one ofwhich is shown in the left hand in Fig. 1, and the other indicated indotted lines upon the right. one side of one of said slots in each ofsaid standards I place a suitably-numbered gage or scale, a, inconnection'with which I prothe apertures a',

vide a ring-clasp or indicator, F, upon which- Upon ICO

. moved elsewhere,

is shown, by preference, a Vernier scale, f. The standards A Aare shownupon di'erent levels G G. The stop-cocks a2 1f-being .open the liquidwithin the tubes assumes the level shownI by the dotted lines y y. Therings F F are moved to indicate this position, and the cocks 'a a2turned to retain said liquid in place, after which the standards may bereif desired, and the scales carefully examined. Should said tubes beoverturnedor the respective altitudes ofthe standards changed too vmuchto correspond with the height of the tubes,the liquid therein is forcedinto one or both of the cups D and the vent c closed, thus preventingleakage.

While I prefer to use two stop-cocks, it is obvious that one mayaccomplish a like purpose, the vsame being placed either upon one of thenecks A, as shown, orat any intermediatcy point between the twostandards.

Having thus described my invention, I claimi 1. The combination, in ahydrostatic level- 'ing-instrument, of the standards A A, united bymeans of a flexible tube, ring-claspsl or indicators F F, one or morestop-cocked2 a', and

conoidal cup-shaped valves D D, with theperforated tops'C, substantiallyas andfor the purposes'speciiied.

2. In ahydrostatic leveling-instrument, the '3o conoidal cup-shapedvalves D D, provided .with supports for loosely sustaining the same insuitable positions respectively near perforations or vents in the topsof the standards, whereby a pressure of liquid within one or the 35other of said valves' may automatically close the vent, substantially asdescribed.

3.l The combination, with the standards, of a hydrostaticleveling-instrument,l ofthe perforated cap-O, valves vD D, and aperforated 4o plate c, for sustaining said cup-valves loosely if? inupright position, substantially as speci- 4'. The combination of theperforated caps C C, cups D D, 4and plates c c, each of the lat- 45 terbeing provided with one or more air-passages at the side of and adjacentto said cups,

substantially as and for the purposes specied.-

JAS. MMJDONALDi- Witnemes:

D. H. FLETCHER, M. M.`GBIDLEY.

